Bathroom Exhaust Fan Repair

[Vikas]

This has me stumped. I have a NuTone 100CFM bathroom fan+light fixture (the big circular light). The fan was spinning slowly and was making bad noises. So I took it apart, cleaned the wheel. It ran great when I tested it by plugging it in to the wall. Very smooth, and lots of air movement! But when I re-install it back, I get some noise and I don't feel the same breeze. I messed around a little bit with the motor mounting nuts and tried to feel if I can locate the place where the fan wheel aka squirrel cage was rubbing somewhere. Nothing jumps out at me but obviously something is wrong because it is not as quiet as it was when plugged in to the wall. I must have taken it down at least three times in an hour, so now I am pretty good at it

Any tricks or suggestions?

 

[doitmyself]

Is there a backflow damper in the unit that might be stuck or is the exhaust line plugged up in another way?

 

[HerrStig]

Check the vent line, it may be partially clogged. A drop of oil on the bearings doesn't hurt. Often those motors have a provision for oiling, but they don't put a big red arrow on it.

 

[JHZR2]

Yeah clog and lube if you can.

Not sure if oil or a grease is the right stuff, and I think you shouldnt oil it too much, just a drop.

Also what about a high resistance connection? The plug in the fan assembly may be corroded and not giving full voltage under load?

 

[demarpaint]

Try cleaning and oiling as others have mentioned, if that doesn't work here's what I've discovered changing a few of them over the years.

How does the fan mount in the bathroom, wall mount, or ceiling mount? The reason I ask is if it is ceiling mounted in the bathroom, plugging it into the wall is positioning the unit differently, and the bearings in the fan motor could be going bad. In some instances just the change of position of the unit can be causing it to perform differently and make noise.

 

[Coprolite]

If all else fails, sometimes the new ones are quieter and more powerful than the one you are trying to fix. I installed one last year in my master bathroom that is orders of magnitude better than all the other ones in the house.

 

[WhyMe]

check for a birds nest in the exhaust. i have seen a couple that had them

 

[DBMaster]

If the unit is more than ten years old make it easy on yourself and buy a new motor at Home Depot or Lowe's and just be done with it.

 

[Quest]

I don't re-lube/service cheep bathroom fans anymore, citing that the quality of components (including those bushings used) are mostly inferior.

I just simply cut to the chase and purchase a new ball-bearing or DC type Panasonic bathroom fan and be over with the issues.

(*besides: they are way more efficient and quiet than most domestic made ones, my 80cfm only runs @ 14Watts, my 120cfm runs @ 23watts).

Q.

 

[Vikas]

I think from the suggestions provided here, the bird's nest might be a possibility. I will need to find a long enough snake.

There are two plugs in the fixture, one for the fan and the one for the light. I will try swapping them.

The fan is mounted up in the ceiling. When I test the fan plugged in to wall, I keep the orientation exactly the same. As I said, the motor and fan both sound just about perfect when I hold it in my hand, so I am little bit reluctant to replace or oil it.

But I would like to get a new Panasonic fan as I have heard they are very quiet but I do not believe the housing would be interchangeable. Replacing the entire box would be beyond my ability.

 

[DBMaster]

Probably not beyond your ability, but not really worth the trouble. How much do you use the thing? I put one of those Broan "upgrade kits" on mine about a decade ago. Still don't use it much.

 

[JHZR2]

Originally Posted By: Quest
I don't re-lube/service cheep bathroom fans anymore, citing that the quality of components (including those bushings used) are mostly inferior.

I just simply cut to the chase and purchase a new ball-bearing or DC type Panasonic bathroom fan and be over with the issues.

(*besides: they are way more efficient and quiet than most domestic made ones, my 80cfm only runs @ 14Watts, my 120cfm runs @ 23watts).

Q.


Have some leads for this??? I have a scoville broan fan box in my bathroom ceiling, I replaced the motor once, but took any number of fans apart at HD because they all mount slightly differently...

Is there such a thing as a universal drop in? Where do the electronics for the panasonic DC fan live?